Spot the mistake!

There is an updated page here.

A great way to get students thinking about mistakes and misconceptions and hence deepen their understanding of topics is to have them mark the work of others. There are some great resources hosted on TES that will allow your students to do just that.


Particularly excellent resources come from Andy Lutwyche, look at his excellent Erica’s Errors seriesfor Spot the Mistake activities. See also, on TES – further Spot the Mistakes resources from Andy Lutwyche.

sim eq


Edexcel’s A Level Teaching and Learning Materials, a growing library of resources offer excellent support for teachers.Edexcel Model Answers
The exemplar answers with examiner comments provide a particularly valuable resource. These booklets look at questions from the AS and A level Sample Assessment Materials, which was used in the trial undertaken in summer 2017. Real student responses are shown together with commentary showing how the examining team apply the mark schemes. The commentary includes always useful notes on common
errors. These could be used in class and students asked to find errors.

Edexcel Model Answers example


TES resources I have come across include:

R Barnard’s Bob’s Ratio Homework 

Craig Barton’s lovely little starter on Algebraic Misconceptions (this one is truly tried and tested – I used it as a starter for a lesson observation and followed it up with a class discussion on what advice students would give to students making the kind of errors here – it went down rather well with the observers!)

Kaszal’s Fractions Mistakes

and Damian Watson’s

Transformations AfL Spot the Mistakes

Enlargement Spot the Mistake Booklet

Fractions AfL Plenary Spot the Mistake Booklet 

Thank you to all the great authors of these resources.


On the subject of mistakes, the Classic Mistakes website has a gallery of posters of classic errors made in Mathematics. These could be a prompt for a useful discussion starter activity. Note that an audio file is also available for each poster.

6 comments on “Spot the mistake!

  1. Good ideas, and something to engage the mind – how do we address misconceptions? I like Nordin’s idea, but instead I keep a camera handy – far more authentic to show it on the screen, provided either the learner is happy with it, or do it anonymously. What about getting them to sign a disclaimer at the start of the year, saying all mistakes will be used for learning experiences. And now I’m thinking, why not have a twitter feed for each class to comment as and when on the pics of the mistakes?
    (One thing I was working on today for a possible blog is how to we provide the learners with the tools for self evaluation. On Friday last, with a very small group of adults, I asked C if her answer was consistent with what she expected; over the last few weeks they’ve got used to wondering if a solution or answer is elegant.)

    • Colin, you mention such an important point here when you mention tools for self evaluation, have you seen the work of John Hattie? We should do everything we can to encourage learners to self assess and work out what to do next.

      • Yes I have, largely through Geoff Petty, who is quite important in the FE sector, and one of the main authors referred to in the teacher training area for post 16. Like a good many things one has to find time for it, but it is time well spent.
        Thanks for reminding me.

      • Hi Colleen. I thought I’d answered you, but I’m just catching up and guess I didn’t. Yes, I have seen John Hattie’s work, and I entirely agree with you. Self assessment also encourage communication and development of technical terms, which I’ve just written a few words about today. Keep up the good work. Colin

  2. Something I like to do is have a blank copy of a test/quiz while I’m marking a set of class papers and copy down the best mistakes into the blank paper. At the end I have a nice resource to give to the students “please help me mark this paper”.

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